Innocent pure beautiful girl Nana Yagi encounters the unknown! Her first attempt at a soapland! A special lecturer from Yoshiwara is invited from a soapland to teach her how to mix lotion and play on the mat. Her first attempt at immediate sex, chair sex, and periscope sex! Even though she's the one providing service, she's so sensitive that she feels all over her body on the mat! If it's such a pleasurable job, she's sure to become addicted! A thrilling first experience for a girl who grew up without any connection to soaplands! Service soapland!